'Took an Oath' in the Bible

And she said to him, My lord, you took an oath by the Lord your God and gave your word to your servant, saying, Truly, Solomon your son will be king after me, seated on the seat of my kingdom.

Then the king swore an oath and said, “As the Lord lives, who has redeemed my soul from all distress,

As I took an oath to you by the Lord, the God of Israel, saying, Certainly Solomon your son will become king after me, seated on my seat in my place; so will I do this day.

Then Solomon took an oath by the Lord: “May God punish me and do so severely if Adonijah has not made this request at the cost of his life.

As the LORD thy God liveth, there is no nation or kingdom, whither my lord hath not sent to seek thee: and when they said, He is not there; he took an oath of the kingdom and nation, that they found thee not.